Collection of handful Python short snippets.

handful-python-short-codes.py

"""Useful short snippets in Python."""


# Return the list of all the file names in the given directory
import os

def get_file_list(file_path):

    files = []
    for root, dirs, files in os.walk(file_path):
        print('# of files: {0}'.format(len(files)))  # can be "pass"
    file_list = files
    return file_list



# Create/delete a directory with 755 permission
import os

path = "/tmp/year"
access_rights = 0o755
## Create
try:  
    os.mkdir(path, access_rights)
except OSError:  
    print ("Creation of the directory %s failed" % path)
else:  
    print ("Successfully created the directory %s" % path)
    
## Delete
try:  
    os.rmdir(path)
except OSError:  
    print ("Deletion of the directory %s failed" % path)
else:  
    print ("Successfully deleted the directory %s" % path)

    
    
# Check whether a file or folder exists:
import os

os.path.isfile('./file.txt')  # file only
os.path.isdir('./dir')  # directory only
os.path.exists('./file.txt')  # file or directory



# Skip header of csv
import csv

with open("in.csv", "rb") as f_csv:
    reader = csv.reader(f_csv)
    next(reader, None)  # skip the headers


    
# Get the current time (as file name timestamp)
import time 

timestamp = time.strftime('%Y%m%d_%H%M%S', time.localtime((time.time())))
print(timestamp)



# To get the current working directory use
import os
cwd = os.getcwd()



# Get the name/OS/platform
import os
os.name
import platform
platform.system()
platform.release()



# Truncate the matplotlib color map
import matplotlib as mpl
from matplotlib import pyplot as plt
import numpy as np

def truncate_cmap(cmap, minval=0.0, maxval=1.0, n=100):  # n is the granularity
    new_cmap = colors.LinearSegmentedColormap.from_list(
        "trunc({n},{a:.2f},{b:.2f})".format(n=cmap.name, a=minval, b=maxval),
        cmap(np.linspace(minval, maxval, n)),
    )
    return new_cmap
new_blues = truncate_cmap(plt.get_cmap("Greens"), 0.4, 0.8, n=100)